Traffic was slow on Phahon Yothin Road's inbound lane from Ratchayothin intersection to the entrance to Lat Phrao Road and along flooded Soi Lat Phrao 80.

Navamindarajudis Bodindecha School in Wang Thong Lang district closed temporarily due to floodwater around the school, traffic police said.

The water was almost pavement high on Sukhumvit Road from Asok intersection to Thong Lor intersection, on Rama III Road near Talad Penang, Sunthorn Kosa Road and the Na Ranong Road intersection.

No relief is in sight, either, as this five-day forecast for the capital region shows.

The Meteorological Department said more heavy rain is forecast for parts of the North and the Central regions until Thursday as an active low pressure cell over the Andaman Sea moves across Myanmar.

Rain is forecast for about 70% of Bangkok and surrounding provinces, with heavy showers in some areas.

According to City Hall's Department of Drainage and Sewerage, 108 millimetres of rain fell on Benchasiri Park in Klong Toey district, 101mm on Klong Samsen in Huai Khwang district, and 94mm on Khlong Saen Saep.

Twitter users said water on several major roads had drained away by 8.30am, but some sois in low-lying areas were still flooded in the aftermath of the storm.